A Chinese farmer has trained his pigs to dive underwater in the belief that it improves their taste and will attract more visitors to his rural home in Hunan province.

Pig breeder Huang Deming has connected the animal's pen to a 10ft chute above a lake. From the age of one month the hogs are made to jump off the chute into the water below three times a day. Some, said Huang, were made to jump 30 times in day.

A pedometer is used to measure the progress of each pig, with the animal only fed after taking a minimum of 2,000 steps and "exercising" for an hour.

Sixty pigs have been trained to dive since last year at his farm in Guanshan village, Ningxiang county, attracting inquisitive tourists and increasing the value of the pigs. Huang claimed that his herd were healthier and grew faster than non-diving pigs and that the exercise regime made the pork leaner and sold for three times as much as ordinary pigs.

Fellow farmer Fan Rong said the animals were attracting investors from around the area.

"Our pigs look and taste better, and they are much sought after. And there are many people who have come to fix a time for purchase, and two heads of such pigs have been booked in advance," she said.

Critics deemed the practice unnecessary and cruel with a video of the diving pigs posted online sparking a furore.

Prof Gu Xianhong of the Chinese Institute of Animal Sciences said: "What this farmer is doing is against the pigs' nature. It merely makes the animals anxious and violates their welfare".

China slaughters roughly 600 million hogs every year, one for every 2.2 people in the country, and consumes half the global output of pig meat, according to Chinese offical statistics.

This demand has been increasing rapidly over the past decade as the country's growing middle classes are consuming more meat.